SAN JOSE, Calif. (KRON) — A COVID-19 outbreak was reported at a San Jose hospital that infected dozens of employees.

43 staff members at the Kaiser Permanente San Jose Medical Center Emergency Department tested positive for COVID-19 between Dec. 27 and Jan. 1, senior vice president and area manager Irene Chavez confirmed Saturday.

The outbreak is being investigated and officials are using contact tracing to notify and test any staff or patients who were exposed during the time period.

Officials are looking into a staff member arriving into the emergency department wearing an air-powered costume on Christmas Day. They say any exposure would have been accidental as the person had no COVID symptoms.

“The individual had no COVID symptoms and only sought to lift the spirits of those around them during what is a very stressful time. If anything, this should serve as a very real reminder that the virus is widespread, and often without symptoms, and we must all be vigilant,” Chavez said in a statement.

Although unconfirmed, Chavez says air-powered costumers will no longer be allowed at the facilities.

Emergency Department staff who received a first dose of the vaccine less than 10 days ago would not be expected to be immune to the virus at the time of the exposure.

Health officials say it is important to note that you must receive the two doses of the vaccine to be protected.

Employees confirmed or suspected to have COVID-19 will not report to work.

All areas in the Emergency Department are undergoing deep cleaning.

Nearly 40,000 Kaiser Permanente health care workers in Northern California have already received COVID-19 vaccinations, and more are anticipated soon.